December 21, 2010 | Wall Street Journal

The Wrong Way to Stop Civilian Terror Trials

Co-Authored with Lee A. Casey

Trying captured al Qaeda, Taliban, or allied terrorists in United States civilian courts is a bad idea. The near-acquittal of Ahmed Ghailani—a key figure in the 1998 attacks on U.S. Embassies in Kenya and Tanzania—in a New York federal court last month proves as much. But one bad idea does not excuse another. Congressional efforts to block future trials by imposing spending restrictions on the president are unconstitutional and should be abandoned.

A provision attempting to do so appeared in the bill, passed by the House on Dec. 8, funding the federal government through next year. That spending bill is dead for now, but the provision is likely to be featured in future appropriations efforts.

The language forbids the use of government funds to transfer detainees now held at Guantanamo Bay to the United States for any and all purposes. Since federal courts sit only in U.S. territory and because criminal defendants must generally be physically within the court's jurisdiction for trial, the apparent purpose of this provision is to prevent President Obama from trying these detainees in federal court.

This is a step too far. The president is the chief federal law enforcement officer and prosecutor. Whether, when and where to bring a particular prosecution lies at the very core of his constitutional power. Conditioning federal appropriations so as to force the president to exercise his prosecutorial discretion in accordance with Congress's wishes rather than his own violates the Constitution's separation of powers.

Congress's powers over federal spending are formidable. The Founders were determined that the president would not be able to raise or spend so much as a single dollar without congressional action. Congress need not authorize spending for any particular purpose, however much the president may insist such spending is necessary, and it may properly condition the use of federal funds.

For example, if Congress votes to appropriate money for road construction, it can condition those funds on states providing some portion of the costs. Similarly, if Congress appropriates money for foreign aid, it can condition release of that funding on the president's certification that a particular recipient government has an acceptable human rights record.

But Congress cannot use its spending power to force the president or the states to surrender their core constitutional authority. Thus, although Congress can require a decent human rights record before U.S. aid flows to a particular regime, it cannot condition federal money on the president's refusal to recognize a particular government, or on his particular exercise of the U.S. veto in the U.N. Security Council. Such decisions—including where, when and how to prosecute—are the president's to make.

This does not mean that Congress is helpless. Although it cannot impose unconstitutional conditions on federal appropriations, as a political matter Congress can link passage of a particular funding bill to the president's agreement to take, or not take, some action Congress desires. Such agreements are not judicially enforceable, but a president who dishonors his commitments will have a very hard time achieving his own legislative goals.

Congress can also limit the use of federal monies in ways that will make it difficult or impossible for the president to pursue a particular policy. While Congress cannot force President Obama to eschew the federal courts in prosecuting al Qaeda members, it can deny him the funding necessary to construct the additional federal prison space that would be necessary in order to close Guantanamo. Here, as in so many other areas, the Constitution cares much more about how something is achieved than the actual result.

If Congress does adopt the funding ban, the president has recourse. He can, and should, execute a presidential signing statement making clear, as President George W. Bush often did, that he will interpret and apply the conditions of the appropriations bill in a manner consistent with the Constitution.

The president should not try the Guantanamo detainees in federal courts. But he cannot permit Congress—whether controlled by Democrats or Republicans—to curtail his own constitutional authority.

Messrs. Rivkin and Casey, Washington D.C.-based attorneys, served in the Department of Justice during the Ronald Reagan and George H.W. Bush administrations.